Display racks are commonly used in supermarkets and other stores to display items of merchandise which are generally sold as self-service items. A common example of the use of display racks is in the display and sale of cans or bottles of soft drinks in supermarkets, the bottles being removed by the customer from the display rack in a self-service manner.
Early designs of display racks comprised a plurality of planar horizontal shelves held in spaced relation by vertical corner posts, with items such as soft drink bottles being arranged in rows from the front to the rear of the shelf. Prospective customers remove the bottles at the front edge of the shelf and proceed to the rear of the shelf until it is empty. The main problem with this prior art shelf design is that it may be difficult for customers to reach bottles on the rear of the shelf, particularly if the shelves are of significant depth or if several shelves are closely spaced one above another. In addition, the merchandise toward the rear of the shelf may be hidden from customers as the shelf is emptied particularly if another shelf is disposed over it.
Merchandising techniques have become more sophisticated in recent years and the shelf structures of display racks have been redesigned in ways which display articles more attractively and provide easy access for customer removal. It has been found highly desirable to provide display racks with shelf structures which are adjustable both angularly and in planar fashion so as to vary the attitude and surface area provided to support self-service items. Angular adjustment of the shelf support may be made in several designs by tilting the front edge of the shelf above the rear edge. In many commercial situations, particularly the storage and display of chilled containers of soft drinks, milk and the like, it is desirable to dispose the rear edge of the shelf above its front edge so that the merchandise can be loaded onto the shelf from the rear and moves forwardly as articles are removed by customers from the front edge of the shelf. In this manner, merchandise is always located in the front portion of the shelf in full view of the customers. It has also been found desirable to provide shelf structures whose width may be expanded or retracted so as to vary the support or surface area provided for the display items. This enables the store to enlarge the surface area of the shelf supporting popular items which sell quickly and lessen the display area of low inventory items or items which do not sell quickly.
Gravity feed shelf assemblies, in which the rear edge of the shelf is adapted to be disposed above the front edge of the shelf, are known and disclosed for example in U.S. Pat. Nos. 3,203,553; 2,443,871; 3,279,618 and 3,900,112. One example of a shelf structure whose length is adjustable is found in U.S. Pat. No. 4,063,518. Although these shelf structures include one or more of the above named preferred features of modern display racks, each have several disadvantages. For example, all of these shelf structures are designed to attach to one type of corner posts or a fixed support. There are currently several designs of corner posts and supports for mounting shelf structures in position. Therefore once replacement shelf supports are needed, owners are forced to purchase either the same shelf supports used previously or new shelf supports and corner posts.
In addition, most shelf structures are provided with an article engaging surface having a coefficient of friction which cannot be varied. In some commercial situations it may be desirable for the article engaging surface to have a low coefficient of friction so that articles readily slide, such as in bottle supporting shelves in which the rear edge of the shelf is angled above the front edge. Other applications may require a higher coefficient of friction to resist article sliding. Existing shelf supports cannot accommodate both situations.
Therefore, it is an object of this invention to provide an adjustable shelf structure having mounting means which are adapted to mount the shelf support to virtually all currently available corner post designs or other fixed shelf supports of a display rack.
It is another object of this invention to provide a shelf structure having a removable aricle support formed with top and bottom article engaging surfaces having different coefficients of friction.
It is a further object of this invention to provide a shelf structure which is angularly adjustable to dispose either the front or rear edge above the other, and which is also adjustable in a planar fashion to vary the surface area of the shelf structure for supporting articles.